Being assertive—polite

Being assertive—polite
I’d like my check now, please.
I’d like my payment now, please.
 No, I don’t think so.
= I totally reject your assertion.
Excuse me?
= Did you really say what  I think you said?
 May I have your name, please?
 I’d like to speak to the manager.
 I’d like to speak to your supervisor .
I intend to stand my ground.
I’m not leaving until I’m satisfied.